From the entry:
Back to today's topic, after setting up my D3D12 rendering framework, I started to learn DirectX ray-tracing (DXR). So I decided to start writing an ambient occlusion demo first because it is easier than writing a full path tracer since I do not need to handle material information as well as the lighting data. The demo can be downloaded from here (required a DXR compatible graphics card and driver with Windows 10 build version 1809 or newer).
In this demo, it renders a G-buffer with normal and depth data. Then a velocity buffer will be generated using current and previous frame camera transform, stored in RG16Snorm format. Then rays are traced from world position reconstructed from depth buffer with cosine weight distribution. To avoid ray-geometry self intersection, ray origin is shifted towards the camera a bit. After that, a temporal and spatial filter is applied to smooth out the noisy AO image and then an optional bilateral blur pass can be applied for a final clean up.
If you're interested in learning more about DX Ray-tracing techniques then check out the full blog post at DXR AO